Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/30—Ion-exchange
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J29/00—Catalysts comprising molecular sieves
  • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
  • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
  • B01J29/08—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the faujasite type, e.g. type X or Y
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
  • C07C2/54—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition of unsaturated hydrocarbons to saturated hydrocarbons or to hydrocarbons containing a six-membered aromatic ring with no unsaturation outside the aromatic ring
  • C07C2/64—Addition to a carbon atom of a six-membered aromatic ring
  • C07C2/66—Catalytic processes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2529/00—Catalysts comprising molecular sieves
  • C07C2529/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites, pillared clays
  • C07C2529/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
  • C07C2529/08—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the faujasite type, e.g. type X or Y

Definitions

• This invention relates to the production of alkylated naphthalenes and substituted naphthalenes.
• Alkylaromatic fluids have been proposed for use as certain types of functional fluids where good thermal and oxidative are required.
• U.S. Pat. No. 4,714,794 (Yoshida) describes the monoalkylated naphthalenes as having excellent thermal and oxidative stability, low vapor pressure and flash point, good fluidity and high heat transfer capacity and other properties which render them suitable for use as thermal medium oils.
• the use of a mixture of monoalkylated and polyalkylated naphthalenes as a base for synthetic functional fluids is described in U.S. Pat. No. 4,604,491 (Dressler) and Pellegrini U.S. Pat. Nos. 4,211,665 and 4,238,343 describe the use of alkylaromatics as transformer oils.
• the alkylated naphthalenes are usually produced by the alkylation of naphthalene or a substituted naphthalene in the presence of an acidic alkylation catalyst such as a Friedel-Crafts catalyst, for example, an acidic clay as described in Yoshida U.S. Pat. No. 4,714,794 or Dressler U.S. Pat. No. 4,604,491 or a Lewis acid such as aluminum trichloride as described in Pellegrini U.S. Pat. Nos. 4,211,665 and 4,238,343.
• an acidic alkylation catalyst such as a Friedel-Crafts catalyst, for example, an acidic clay as described in Yoshida U.S. Pat. No. 4,714,794 or Dressler U.S. Pat. No. 4,604,491 or a Lewis acid such as aluminum trichloride as described in Pellegrini U.S. Pat. Nos. 4,211,665 and 4,238,343.
• a catalyst described as a collapsed silica-alumina zeolite as the catalyst for the alkylation of aromatics such as naphthalene is disclosed in Boucher U.S. Pat. No. 4,570,027.
• various zeolites including intermediate pore size zeolites such as ZSM-5 and large pore size zeolites such as zeolite L and ZSM-4 for the alkylation of various monocyclic aromatics such as benzene is disclosed in Young U.S. Pat. No. 4,301,316.
• the preferred alkyl naphthalenes are the mono-substituted naphthalene since they provide the best combination of properties in the finished product: because the mono-alkylated naphthalenes posses fewer benzylic hydrogens than the corresponding di-substituted or polysubstituted versions, they have better oxidative stability and therefore form better functional fluids and additives.
• the mono-substituted naphthalenes have a kinematic viscosity in the desirable range of about 5-8 cSt (at 100° C.) when working with alkyl substituents of about 14 to 18 carbon atoms chain length.
• the mono-alkylated naphthalenes may be obtained in admixture with more highly alkylated naphthalenes using conventional Friedel-Crafts catalysts such as those mentioned above or by the use of zeolites such as USY, the selectivity to the desired mono-alkylated naphthalenes is not as high as desired.
• catalyst containing a roughly 50/50 (molar basis) of NH4 and H gave unexpectedly superior results. Phrased another way, catalyst which was exchanged with ammonia, and then only about half calcined, gave better results than catalyst which was wholly in the ammonium form, or calcined to be in the protonic form. Although the performance of the catalyst could be improved by the incorporation of rare earths, we were able to make excellent catalyst with essentially no rare earths present.
• the present invention provides a process for preparing long chain alkyl substituted naphthalenes which comprises alkylating a naphthalene with an alkylating agent possessing an alkylating aliphatic group having at least six carbon atoms under alkylation reaction conditions in the presence of an alkylation catalyst comprising a porous crystalline zeolite containing exchangeable sites and both ammonium and protonic species associated with said exchangeable sites, and wherein the ratio of ammonium:protonic species is within the range of 95:5 to 5:95, molar basis, to form an alkylated naphthalene possessing at least one alkyl group derived from the alkylating agent.
• the present invention provides a process for preparing long chain alkyl substituted naphthalenes which comprises reacting naphthalene with a olefin containing at least 8 carbon atoms as an alkylating agent under alkylation reaction conditions and in the presence of an alkylation catalyst comprising an ultrastable Y zeolite with exchangeable sites containing both ammonium and protonic species associated with said exchangeable sites, and wherein the molar ratio of ammonium:protonic species is from 65:35 to 35:65 to form an alkylated naphthalene possessing at least one alkyl group derived from the alkylating agent.
• the starting materials for the production of the alkylated naphthalenes are naphthalene itself as well the substituted naphthalenes which may contain one or more short chain alkyl groups containing up to about eight carbon atoms, such as methyl, ethyl or propyl.
• Suitable alkyl-substituted naphthalenes include alpha-methylnaphthalene, dimethylnaphthalene and ethylnaphthalene.
• Naphthalene itself is preferred since the resulting mono-alkylated products have better thermal and oxidative stability than the more highly alkylated materials for the reasons set out above.
• the alkylating agents which are used to alkylate the naphthalene include any aliphatic or aromatic organic compound having one or more available alkylating aliphatic groups capable of alkylating the naphthalene.
• the alkylatable group itself should have at least about 6 carbon atoms, preferably at least about 8, and still more preferably at least about 12 carbon atoms.
• the alkyl groups on the alkyl-naphthalene preferably have from about 12 to 30 carbon atoms, with particular preference to about 14 to 18 carbon atoms.
• a preferred class of alkylating agents are the olefins with the requisite number of carbon atoms, for example, the hexenes, heptenes, octenes, nonenes, decenes, undecenes, dodecenes. Mixtures of the olefins, e.g. mixtures of C 12 -C 20 or C 14 -C 18 olefins, are useful. Branched alkylating agents, especially oligomerized olefins such as the trimers, tetramers, pentamers, etc., of light olefins such as ethylene, propylene, the butylenes, etc., are also useful.
• alkylating agents which may be used, although less easily, include alcohols (inclusive of monoalcohols, dialcohols, trialcohols, etc.) such as hexanols, heptanols, octanols, nonanols, decanols, undecanols and dodecanols; and alkyl halides such as hexyl chlorides, octyl chlorides, dodecyl chlorides; and higher homologs.
• alcohols inclusive of monoalcohols, dialcohols, trialcohols, etc.
• alkyl halides such as hexyl chlorides, octyl chlorides, dodecyl chlorides; and higher homologs.
• the alkylation reaction between the naphthalene and the alkylating agent is carried out in the presence of a zeolite catalyst which contains a cation of certain specified radius.
• the molecular size of the alkylation products will require a relatively large pore size in the zeolite in order for the products to leave the zeolite, indicating the need for a relatively large pore size in the zeolite, which will also tend to reduce diffusion limitations with the long chain alkylating agents.
• the large pore size zeolites are the most useful zeolite catalysts for this purpose although the less highly constrained intermediate pore size zeolites may also be used, as discussed below.
• the large pore size zeolites are zeolites such as faujasite, the synthetic faujasites (zeolites X and Y), zeolite L, ZSM-4, ZSM-18, ZSM-20, mordenite and offretite which are generally useful for this purpose are characterized by the presence of a 12-membered oxygen ring system in the molecular structure and by the existence of pores with a minimum dimension of at least 7.4 ⁇ , as described by Frilette et al. in J. Catalysis 67,218-222 (1981 ). See also Chen et al. Shape-Selective Catalysis in Industrial Applications, (Chemical industries; Vol.
• the large pore size zeolites may also be characterized by a "Constraint Index" of not more than 2, in most cases not more than 1.
• Zeolite beta a zeolite having a structure characterized by twelve-membered pore openings, is included in this class of zeolites although under certain circumstances it has a Constraint Index approaching the upper limit of 2 which is characteristic of this class of zeolites. The method for determining Constraint Index is described in U.S. Pat. No. 4,016,218, together with values for typical zeolites and of the significance of the Index in U.S. Pat. No. 4,861,932, to which reference is made for a description of the test procedure and its interpretation.
• Zeolites whose structure is that of a ten membered oxygen ring, generally regarded as the intermediate pore size zeolites may also be effective catalysts for this alkylation reaction if their structure is not too highly constrained.
• zeolites such as ZSM-12 (Constraint Index 2) may be effective catalysts for this reaction.
• the zeolite identified as MCM-22 is a useful catalyst for this reaction. MCM-22 is described in U.S. patent application Ser. No. 07/254524, filed 6 Oct. 1988 and also in International Patent Application PCT/U.S. 88/04251, to which reference is made for a description of this zeolite.
• zeolites having a CI up to about 3 will generally be useful catalysts, although the activity may be found to be dependent on the choice of alkylating agent, especially its chain length, a factor which imposes diffusion limitations upon the choice of zeolite.
• a highly useful zeolite for the production of the monoalkylated naphthalenes is ultrastable Y, usually referred to as USY. When this material contains hydrated cations, it catalyses the alkylation in good yields with excellent selectivity.
• Zeolite USY is a material of commerce, available in large quantities as a catalyst for the cracking of petroleum. It is produced by the stabilization of zeolite Y by a procedure of repeated ammonium exchange and controlled steaming. Processes for the production of zeolite USY are described in U.S. Pat. Nos.
• Y zeolite in the 0.2 to 0.4 micron range, although the 0.6 to 1.3 micron material which is more typical of Y zeolite crystals may also be used.
• the zeolite It is essential to put the zeolite in a form in which the cation exchange sites contain both ammonium and protonic species. Expressed as % of total ion exchange capacity, the zeolite should contain at least 35% ammonium and at least 35% protonic. Preferably, the ammonium and protonic forms each occupy at least 40% of the available sites. Most preferably the ammonium form is 55 to 50% of the available sites, with the protonic form being the remainder.
• the total ion exchange capacity of the catalyst may be determined by the temperature programmed ammonia desorption method described by G. T. Kerr and A. W. Chester in Thermochimica Acta, 3, 113-124 (1971), which is incorporated by reference.
• This ratio, of ammonium to protonic forms, may also be expressed in terms of a standardized calcination procedure after ammonium exchange.
• the zeolite may be placed in the ammonium form using conventional techniques. Typically this involves contacting the zeolite, or catalyst, with 5 vol/vol of N N NH4NO3 and stirring for an hour, water washing, another exchange step, and a final wash. The catalyst then may be calcined for 5 hours in flowing air. When this procedure is used, calcining for 400-425 gives optimum results.
• the selected zeolite catalyst preferably contains a limited amount of one or more of the Rare Earths. Suitable are Y, La and any of the Lanthanum Series of Rare Earths, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb, and Lu. Especially preferred are Ce, Y and La. In most applications, mixtures of rare earths will be preferred, as these are readily available commercially and much less expensive than purified rare earth elements. The mixed rare earths typically used to produce zeolite Y based cracking catalysts serve well.
• the zeolite does not contain the desired amount of rare earths they may be introduced by ion-exchange in the conventional manner using a solution of the exchanging cation.
• the optimum RE content will be about 1 wt %, equivalent to a rare earth content corresponding to less than about 15% of the total number of exchangeable sites.
• Binders may be used to improve crush strength and other physical properties. Suitable materials include naturally occurring clays, e.g., bentonite and kaolin as well as silica, alumina, and mixtures thereof.
• the relative proportions of zeolite, present in finely divided crystalline form, and oxide matrix may vary widely, with the crystalline zeolite content ranging from about 1 to about 90 percent by weight and more usually, particularly when the composite is prepared in the form of beads, in the range of about 2 to about 80 weight percent of the composite.
• the stability of the alkylation catalyst of the invention may be increased by steaming.
• U.S. Pat. Nos. 4,663,492; 4,594,146; 4,522,929; and 4,429,176 describe conditions for the steam stabilization of zeolite catalysts which can be utilized to steam-stabilize the catalyst. Care should be taken to ensure that steaming conditions are not so severe as to convert too much of the ammonium species to protonic species.
• the alkylation process of this invention is conducted such that the organic reactants, i.e., the alkylatable aromatic compound and the alkylating agent, are brought into contact with the zeolite catalyst in a suitable reaction zone such as, for example, in a flow reactor containing a fixed bed of the catalyst composition, under effective alkylation conditions.
• a suitable reaction zone such as, for example, in a flow reactor containing a fixed bed of the catalyst composition, under effective alkylation conditions.
• Such conditions typically include a temperature of from about 100° C.
• WHSV feed weight hourly space velocity
• alkylatable aromatic compound to alkylating agent mole ratio of from about 0.1:1 to about 50:1, preferably from about 4:1 to about 1:4 e.g. from about 2:1 to about 1:2.
• the WHSV is based upon the weight of the catalyst composition employed, i.e., the total weight of active catalyst (and binder if present).
• Preferred reaction conditions include a temperature within the approximate range of from about 100° C.
• the pressure should preferably be maintained at a value of at least about 50 psig in order to prevent the naphthalene from subliming into the overhead of the alkylation reactor; the required pressure may be maintained by inert gas pressurization, preferably with nitrogen.
• the reactants can be in either the vapor phase or the liquid phase and can be neat, i.e., free from intentional admixture or dilution with other material, or they can be brought into contact with the zeolite catalyst composition with the aid of carrier gases or diluents such as, for example, hydrogen or nitrogen.
• the alkylation can be carried out as a batch-type reaction typically employing a closed, pressurized, stirred reactor with an inert gas blanketing system or in a semi-continuous or continuous operation utilizing a fixed or moving bed catalyst system.
• the presence of some water may improve selectivity, e.g., operation with water addition to the feed or hydration of the catalyst.
• selectivity e.g., operation with water addition to the feed or hydration of the catalyst.
• For a fluid bed reactor operation with about 0.75 wt % water in the reaction mixture is preferred.
• the products comprising alkylated aromatics are characterized by exceptional oxidative and thermal stability. They may be separated from the reaction mixture by stripping off unreacted alkylating agent and naphthalene compound in the conventional manner. It has also been found that the stability of the alkylated product may be improved by filtration over activated charcoal and by alkali treatment to remove impurities, especially acidic by-products formed by oxidation during the course of the reaction.
• the alkali treatment is preferably carried out by filtration over a solid alkali material, preferably calcium carbonate (lime).
• the RBOT (Rotating Bomb Oxidation Test) stability can be increased from a value of 184 minutes for an unstripped product (C 14 -alkylnaphthalene) to 290 minutes if the unreacted materials are removed by stripping and to 350 minutes if the stripped product is filtered over lime (CaCO 3 ).
• the total ion exchange capacity of the catalyst as determined by temperature programmed ammonia desorption is 1.09 meq/g.
• Catalyst D the catalyst with the ammonium cation concentration of 0.59 meq/g, is the most effective catalyst for this reaction. Only 54% of the exchangeable sites of this catalyst are in the ammonium form, the remainder are in the hydrogen form. This example demonstrates that only a fraction of the exchangeable sites need to contain a cation for the catalyst to be effective.
• This catalyst was ion exchanged with ammonium nitrate using the procedure described in Example 1 and then calcined at 400° C. in flowing air for five hours to produce Catalyst H.
• Another catalyst, Catalyst I was prepared from the same base ammonium exchanged material by calcining at 538° C. in flowing air for five hours.
• Example 3 Five parts of each of the catalysts of Example 3 were combined with ninety-five parts of naphthalene and 1-hexadecene in a 1:1.2 molar ratio in a stirred vessel. The contents of the vessel were then heated to 200° C. and held at this temperature for four hours. The contents of the vessel were analyzed using gas chromatography to determine the amounts of unreacted naphthalene, olefin, monoalkylate and dialkylate. The results are summarized below:
• Catalyst J Five parts of Catalyst J, a commercially available rare earth containing USY (REUSY) catalyst having the properties shown below were combined with ninety-five parts of naphthalene and 1-hexadecene in a 1:1.2 molar ratio in a stirred vessel.
• REUSY rare earth containing USY
• the contents of the vessel were then heated to 200° C. and held at this temperature for four hours.
• the contents of the vessel were analyzed using gas chromatography to determine the amounts of unreacted naphthalene, olefin, monoalkylate and dialkylate. The results are summarized below:
• Catalyst K a commercially available rare earth containing USY (REUSY) catalyst having the properties shown below were combined with ninety-five parts of naphthalene and 1-hexadecene in a 1:1.2 molar ratio in a stirred vessel.
• REUSY rare earth containing USY
• the contents of the vessel were then heated to 200° C. and held at this temperature for four hours.
• the contents of the vessel were analyzed using gas chromatography to determine the amounts of unreacted naphthalene, olefin, monoalkylate and dialkylate. The results are summarized below:
• Example 5 Comparison of the results of Examples 5 and 6 show that the rare earth content of the catalysts can affect yields and that the lower rare earth concentration (i.e., 1 wt. %) is preferred.
• the rare earth content of the preferred catalyst (Example 5) catalyst would correspond to less than 15% of the total number of exchangeable sites.
• the zeolites were incorporated into a silica-clay matrix at a 40 wt. % zeolite level.
• one part of colloidal silica (Nalco 1034A) was mixed with one part of a Thiele RC-32 clay, charged as a slurry.
• the ammonium exchanged samples were calcined at either 572° F. (300° C.) or 752° F. (400° C.) to leave different levels of ammonia on the catalysts.
• the calcination consisted of heating the samples in flowing air (5 vol air/vol catalyst/min) from room temperature to the target temperature at 5° F./min. The catalysts were then held at the final temperature in flowing air for 5 hours.
• the fully calcined samples (1000° F.) were produced in a similar manner but were not ammonium exchanged prior to final calcination.
• Temperature programmed ammonia desorption was carried out using the method described by Kerr and Chester. Typically, the sample was heated in the DuPont Model 951 TGA from room temperature to 700° C. at 10° C./minute under a 150 ml/minute flow of high purity helium. The stream of helium containing the desorbed ammonia was passed through a buffered solution where the excess base was titrated with sulfamic acid solution of known concentration (usually ⁇ 0.017 g N/l). The exchange capacity is reported as milliequivalents of ammonia per gram of catalyst (meq/g) based on the weight of the catalyst determined at 700° C.

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• 1993
  • 1993-12-27 US US08/173,006 patent/US5457254A/en not_active Expired - Lifetime
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  • 1994-12-19 AU AU15159/95A patent/AU675612B2/en not_active Ceased
  • 1994-12-19 WO PCT/US1994/014707 patent/WO1995018083A1/en active IP Right Grant
• 1995
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